The present invention relates generally to telecommunications systems and methods for positioning a target mobile station within a cellular network, and specifically to providing position related services based on the calculated location of the target mobile station.
Determining the geographical position of an mobile subscriber within a cellular network has recently become important for a wide range of applications. For example, location services (LCS) may be used by transport and taxi companies to determine the location of their vehicles. In addition, for emergency calls, e.g., 911 calls, the exact location of the mobile subscriber may be extremely important to the outcome of the emergency situation. Furthermore, LCS can be used to determine the location of a stolen car, for the detection of home zone calls, which are charged at a lower rate, for the detection of hot spots for micro cells, or for the subscriber to determine, for example, the nearest gas station, restaurant, or hospital, e.g., xe2x80x9cWhere am Ixe2x80x9d service.
In some instances, the mobile subscriber or the cellular network currently serving the mobile subscriber may not want to provide the location information to the requesting LCS client. For example, the mobile subscriber may not want his or her location to be provided when that subscriber is at home, at work or at a location that the mobile subscriber would like to restrict positioning. Likewise, the network may not want to provide location information when the mobile subscriber is in an area that requires secrecy, such as a military base, government office, police station or other area that the network would like to restrict positioning.
Currently, to prevent an LCS client from obtaining location information, a mobile subscriber can define a Subscriber Location Privacy Profile (SLPP), which indicates which LCS clients are allowed to position the mobile subscriber and in which locations those LCS clients are allowed to position the mobile subscriber. However, the allowed or disallowed location (s) can only be defined by network area, such as by cell or Location Area (LA), all of which typically cover a large geographical region. This is due to the fact that the SLPP is only used in an initial determination of whether or not the LCS client is allowed to position the mobile subscriber. This determination is typically performed before the geographical location information is calculated, which requires the determination to be made based upon the network area that the mobile subscriber is currently located in.
If the restricted area covers only a portion of a network area, such as a cell, defining an entire network area as a disallowed area unnecessarily prevents an LCS client from obtaining location information. In addition, if the network determines that a portion of a network area should be restricted from positioning, the network must prevent all positioning from being performed in the entire network area. This is undesirable for both the network and the mobile subscriber.
The present invention is directed to telecommunications systems and methods for defining restricted positioning areas by geographical location. The restricted area information can be established by the cellular network or the mobile subscriber, and can be stored in a database, such as an Intelligent Network (IN) node. An IN trigger can be included in the subscriber information provided to the serving Mobile Switching Center/Visitor Location Register (MSC/VLR) or the IN trigger can be stored in specific MSC/VLR""s that have restricted positioning areas for all mobile subscribers. Upon receiving the calculated location estimate, the IN trigger is activated, and the MSC/VLR transmits the calculated location estimate to the IN node to determine whether the calculated location estimate can be provided to the requesting LCS client based upon the defined restricted area information.